Catalog SEO Configuration and Store View Scope
Compare the destination with URL rewrites and product assignment to the website. An adopted URL key of a removed product may remain unattainable.
Compare canonical settings for products and categories in the effective configuration range. A store view can override an inherited value; layered navigation extensions can also bring in their own rules.
Where to check the setting in Magento
Under Stores → Configuration → Catalog → Catalog → Search Engine Optimization, check the canonical specifications for products and categories in the right scope. Also, compare URL rewrites and extensions for layered navigation. A Store View deviation must not be obscured by a global setting.
Example of this specific finding
Illustrative control case: /article/? ref=mail refers via canonical to /alter-article/, the target answers with 404. The preferred address no longer contains the intended article.
follow-up audit in Magento
Compare a product via direct and category path as well as a filter page. Do not force all filter combinations to the same address without checking their contents.
Determine the appropriate achievable goal and correct the canonical source. Then retrieve the source page and destination separately.
Derogations and scope
Any achievable goal is not a substitute. If the article no longer exists, first clarify the publishing state instead of just the canonical field.
Reference: Magento Open Source or Adobe Commerce with classic storefront. Consider store views and extensions; other storefront architectures have their own configurations.
Classify the general error
Definition, system-independent causes and further correction examples: The preferred target must have the intended content